The present invention relates to a heat pump device comprising a water-cooling heat exchanger for taking heat of a refrigerant which enters expansion means, and a drying machine comprising the heat pump device.
There has heretofore been a drying machine in which an electric heater or a gas burning heater is used as a heat source. After heating outside air by the electric heater or the burning heater to form high-temperature air, the air is blown into a storage chamber in which a matter to be dried is stored to dry the matter to be dried in the storage chamber. Moreover, the high-temperature air in the storage chamber, which has dried the matter to be dried, is discharged to the outside.
However, in the drying machine using the electric heater or the gas burning heater, outside air containing moisture at low temperature outside the storage chamber is used in the high-temperature air to be fed into the storage chamber. Therefore, much time is required until the matter to be dried is dried. Therefore, energy consumption for drying the matter to be dried increases, and there has been a problem that energy costs such as charges for electricity and gas are soaring.
To solve the problem, a clothing drying machine has been developed which is constituted of a compressor, a heating coil, an expansion valve, and a cooling coil. A heat pump capable of circulating a heat exchange medium is utilized. The matter to be dried is dried by the high-temperature air heated by the heating coil. Moisture evaporated from the dried matter is condensed and removed from the air by the cooling coil, and the condensed water is discarded (see, e.g., Japanese Patent Application Laid-Open No. 11-99299).
However, especially, in the drying machine such as a dry cleaner using a solvent as a washing liquid, it is necessary to recover the solvent by lowering of refrigerant evaporation temperature in an evaporator at a predetermined temperature or less. Therefore, the refrigerant before expanding in the heat pump device is cooled. In this cooling of the refrigerant before expanding, a water-cooling heat exchanger is used. A city water piping is extended through this heat exchanger, and a water amount adjustment valve controls the amount of water passing through the city water piping. Therefore, there is a case where that scales are generated depending on quality of the city water circulated through the city water piping, and there is a fear that the water amount adjustment valve or the like is clogged with these scales.
To solve the problem, in a water circuit of a hot-water supplying device and the like provided with a conventional heat pump device, it is detected whether or not the water circuit is clogged by calculating of a hot-water supplying capacity of the device based on data of a flow rate sensor and refrigerant temperature sensors disposed before and after the gas cooler.
However, since the flow rate sensor is expensive, there is a problem that the cost of the whole system becomes high, and there has been a demand for development of a method for detecting clogging of the water circuit without using any flow rate sensor.